Bob
We love our 2720SL. We just spent 10 days in it. Two people three dogs (two German Shepherds & 1 Boston Terrier). We left the chair behind and added a small foldup table from CW that fits perfectly between the refridge and the slide out along the window. We like the open feel of this model. The tables don't bother us (outboard one slides out with a leaf to make it double wide). Since you pretty much have to sit up to eat in either the couch or the diner style that isn't a problem. The dinette seems to make the space seem smaller and doesn't seem as easy to take a nap in.
The couch is real handy for that! I built a coat tree out of a piece of redwood 2x2 and some brass hooks that sits nicely by the door to hang coats, hats, leashes, etc. on. Definitely reduces clutter when you are staying for a while. We also have the hanging cabinet.
With the dinette wouldn't you have to have that table up all the time, or set it up/take it down for meals? Then you are always having to slide in and out or sit on the edge facing the table. When you are home do you sit around the table most of the time or do you prefer a couch with a few comfortable pillows and/or an easy chair? We also use one of our foldable lounge chairs inside sometimes.
If we ever needed the extra sleeping space it seems like the couch would be more comfortable than the converted dinette. But, in the end, it really boils down to how you are going to use the space and what "feels" right to you. In some ways its like any home buying experience. Weirdly enough I paid almost the same for our TM as for my first house. :-/
Jim